Fluid-pressure brake device



W. V. TURNER.

FLUID PRESSURE BRAKE DEVICE.

APPLICATION FILED AUG-22, 1.918.

1,839,679. Patented May 11,1920.

n wEN'ron WolrerV'lDmeb Y 0/4110! ITED- STATES PATENT ore-non WALTER Manama, or wrnxmsnune, PENNSYLVANIA, nssrenon 'ro wns'rmenousn AIR'IBRAKE COMPANY, or WILMERDING, PENNSYLVANIA, A com'omrron' To all whom it may concern:

O1 PENNSYLVANIA.

FLUID-PRESSURE BRAKE DEVICE.

. Patented May 11, 1920.

Application filed August 22, 1918. Serial No. 250,938.

Be itknown that I, WALTER V. TURNER, a citizen of the United States, residing at Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Fluid-l Pressure Brake Devices, of which the following is a specification.

This invention relates to fluid pressure brakes, and more particularly to a brake pipe pressure maintainin device.

The principal object 0 my invention is to provide an improved device for. maintaining the pressure in the brake pipe at anyde ired degree.

1n the accompanying drawing, the single figure is a view, partly in section, of a loco motive brake apparatus for controlling the brake pipe pressure, showing my invention ap lied thereto. v

s shown in the'drawing, the construction may comprise a'brake valve device 1, a brake pipe 2, a main reservoir 3, an equalizing reservoir 4, and a brake pipe pressure maintaining valvedevice 5.

The brake pipe; pressure maintaining valve device 5 may comprise a casing, having a piston chamber 6, connected by passage 7 to a pipe 8 leading to the equalizing reservoir 4 and to the brake valve 1, and containing a piston 9, and having a. valve Y 1 chamber 10, connected to brake p1pe'2 and containing aslide valve 11 adapted to be operated by piston 9 -for venting fluid from the valve chamber .10 and-the brake pipe 2 -The casing also has a valve chamber 12,

connected to main reservoir ipe 13 and con- .taining a slide valve 14, a apted to be operated by piston 9 for supplyingfluid under pressure from themain reservolr 3. to valve chamber 10 and to brake pipe 2.

The brake valve device 1 may comprise the usual casing," having a valve chamber 15, connected byipassa e 17 to-passage '16, which supplies fluid un er' pressure from the main reservoir to the feed valve device 18 of the usual construction and containing a rotary valve 19 adapted to be operated by handle 20.

lln operation, if the brake valve handle is turned to running position, as shown in the drawing, fluid under pressure is supplied from the main reservoir 3, at the p'rrssure at which the feed valve device 18 may be adjusted, to the equalizing reservoir 4 and the piston chamber 6, through passage 21,

admit fluid from the main reservoir '3 to valve chamber 10 and the brake pipe 2.

When the pressure in the brake pipe 2 and valve chamber 10 has been increased to a degree slightly less than the pressure supplied'to the piston chamber 6 and corresponding with the setting of feed valve 18, the pressure acting on the inner face of piston 9, aided by t e spring sto 24:, causes the movement of piston 9 and t e valves 11 and 14 to lap position.

If the brake pipe pressure should fall below the degree at which the brake pipe ressure is to be maintained, due to leakage rom the brake pipe, the higher pressure in piston chamber 6 will then actuate the piston 9 so as to again open the valve 14 and sup ply fluid to the brake pipe to compensate for the brake pipe leakage.

In order to make a reduction in brake;

pipe pressure to efl'ect an application of the brakes, the brake valve handle 20 is turned to application position, in which fluid is vented from the equalizing reservoir When' the pressure in the equalizing res- .ervoir has been reduced to a point corresponding with the desired reduction in brake l pipe pressure, the brake valve is lapped, and.

when the brake pipe pressure has reduced to a degree slightly less than the pressure in piston chamber 6, the piston 9 will move the valve 11 to lap position thus cutting off the further venting of fluid from the brake pipe.

Having now described my invention, what I claim as new, Letters Patent, is

1. In a fluid pressure brake, the combination with a brake pipe, an equalizing valve device, a feed valve device, and a brake valve havlng a position for supplying fluid from the'teed valve device to the equalizing reservoir, of a valvedevice subject to the opand desire to secure by posing pressures of the brake pipe and the equalizing reservoir for supplying fluid to the brake pipe, said valve device being the sole source of fluid pressure supply for the brake pipe.

2. In a fluid pressure brake, the combination with a brake pipe and an equalizing reservoir, of: a valve device subject to the opposing pressures of the brake p1pe and the equalizing reservoir for supplying and releasing fiuid to and from the brake pipe.

3. In a fluid pressure brake, the combination with a brake pipe, an equalizing reservoir, and a brake valve for varying the pressure in the equalizing reservoir, of a valve device having a piston subject to the opposing pressures of the equalizing res ervoir and the brake pipe and valve means operated by said piston for supplying and releasing fluid to and from the brake pipe.

4. In a fluid pressure brake, the combination with a brake pipe, an equalizing res-' ervoir, and a brake valve for varying the pressure in the equahzmg reservolr, of a valve device havin a valve for supplylng fluid to the brake pipe, a valve'for releasing fluid from the brake pipe, and a iston', subject to the opposing pressures oi the brake pipe and the equalizing reservoir for operating said valves.

5. In a fluid pressure brake, the combination with a brake pipe and an equalizing reservoir, of valve means for supplying and releasing fluid to and from the brake pipe and having an intermediate lap position, and a piston subject to the opposing pressures of the brake pipe and the equalizing reservoir for operating said valve means.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER. 

